The present invention relates to a rotatable tool head for a machine tool, including a base member mounted to a rotatable tool spindle for rotation therewith, a tool slide carrying a facing tool and slideably mounted in the base member so as to be lineally movable in a radial direction for tool adjustments, a counter slide arranged to be lineally movable in a direction opposite to the direction of movement of the tool slide for mass balancing, and actuating means for simultaneously displacing the tool slide and counter slide.
A rotatable facing tool head of this type has become known from German printed application 34 08 352. In this known tool head the tool slide and the mass balancing counter slide are arranged in axial adjacent relationship such that their mass centers move along radial lines axially spaced with respect to each other. When the tool head is rotating this arrangement provides for unbalanced masses causing "wobble" forces when the tool head is rotating.
U.S. Pat. No. 3,824,883 discloses a rotatable facing tool head having a pair of tool slides which are positioned adjacent to each other in the same radial plane such that the mass centers of the two tool slides move along radially spaced lines when the tool slides are displaced in opposite directions. Also, with this known rotatable tool head "wobble" forces are generated by unbalanced masses resulting from the radially adjacent arrangement of the tool slides.
It is a primary object of the present invention to provide a rotatable tool head having a tool slide and a counter slide arranged so that unbalanced masses are substantially eliminated.
According to the present invention a rotatable tool head of the above identified type is characterized in that the counter slide is slideably mounted in a central recess of the tool slide such that the mass centers of the tool slide and the counter slide move along substantially the same radial line during tool adjustments.
Accordingly the mass balancing counter slide is "integrated" within the tool slide by being mounted in the central recess of the tool slide. When both slides are simultaneously displaced in opposite directions, their mass centers move along substantially the same radial line intersecting the axes of the tool shaft. Due to this arrangement there are substantially no unbalanced masses, and no "wobble" forces exist.
The actuating means for displacing the slides may comprise a tooth gearing or any other mechanical or hydraulic mechanism.